Stabilization of 6, 7, 8, 9, 10, 10-hexachloro-1, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 4, 3-benzodioxathiepin-3-oxide with nitrogen containing compounds



United States Patent Ofitice 3,078,277 Patented Feb. 19, 1963iTABILIZATION OF 6,7,8,9,10,10-HEXACHLORO- 1,5,5a,6,9,9a-HEXAHYDRO 6,9METHANO-2,4,3- BENZODIOXATHIEPIN-B-OXIDE WITH NITRO- GEN CONTAININGCOMPOUNDS Emil J. Gearing, Grand Island, N.Y., assignor to HookerChemical Corporation, Niagara Falls, N.Y., a corporation of New York NoDrawing. Filed Mar. 23, 1959, Ser. No. 800,951

10 Claims. (Cl. 260-327) This invention relates to a process forstabilizing 6,7,8, ),10,l hexachloro l,5,5a,6,9,9a hexahydro 6,9-nethano 2,4,3-benzodioxathiepin-3-oxide, hereinafter referred to asThiodan, a registered trademark of Farbwerke Hoechst Aktiengesellshaftand to the new and stable com- Jositions which are produced thereby.

Thiodan" may be represented structurally as follows:

Thiodan" may best be prepared by the method disclosed in copendingapplication S.N. 733,500, filed May 7, 1958, now US. Patent No.2,983,732. Therein cis-2- buten-l,4-diol is slowly added to an excess ofhexachloro- :yclopentadiene in the presence of a compound selected fromthe group consisting of alkali metal carbonates, alkaline earth metalcarbonates, epoxides and mixtures thereof, and in the presence of asolvent. The Diels-Alder adduct thus obtained is then reacted withthionyl chloride to give Thiodan.

Thiodan finds utility primarily as a herbicide, fungicide, andinsecticide. Thiodan may also be used for protecting wood, paper,textiles and leather. Furthermore, Thiodan may be used as adisinfectant.

Commercial Thiodan is a solid which is susceptible to decomposition onstorage under normal conditions. it should be pointed out that Thiodandiffers markedly from other chlorinated Diels-Alder type insecticides inthat it contains a sulfite ring. This presents unique stabilizationproblems. The rate of decomposition varies from an insignificant degreeto several percent per week, and the rate is accelerated upon exposureto ultraviolet light. The decomposition products of Thiodan includel,4,5,6,7,7 hexachloro 2,3 -bis(hyclroxymethyl) bi-:yclo-(2.2.1)-heptene-5, also known as l,4,5,6,7,7-hexachlorobicyclo(2.2.1) hept 5 ene 2,3 dimethanol, and sulfur dioxide. Hydrogen chlorideis evolved from some samples of 'lhiodan." These decomposition productshave little if any pesticidal activity of the type exhibited by Thiodan.The formation of 1,4,5,6,7,7- hexachloro 2,3 bis(hydroxymethyl) bicyclo(2.2.1)- heptene-S is undesirable because of its slight solubility inthe solvents generally used in Thiodan formulations. The formation ofsulfur dioxide and hydrogen chloride is undesirable because of theirdisagreeable odors. In addition, hydrogen chloride destroys thecontainers normally used to store Thiodan, for example, standard fiberdrums containing commercial Thiodan" were weakened after thirty days tosuch an extent that the Thiodan spilled out onto the floor and thelacquered metal lids were severely corroded.

It is the primary object of this invention to provide a stable Thiodan"composition.

It is a further object of the present invention to provide a method forpreventing the loss of pesticidal activity of Thiodan during storage.

It is a still further object of the present invention to provide amethod for preventing the formation of insoluble l,4,5,6,7,7 hexachloro2,3 bis(hydroxyrnethyl)- bicyclo-(2.2.l )-heptene-5.

It is a still further object of the present invention to provide amethod for preventing the formation of undesirable gases such as sulfurdioxide and hydrogen chloride.

A further object of the present invention is to provide a method forpreventing the disintegration of Thiodan storage containers.

Another object of the present invention is to provide a method forprolonging the pesticidally-efiective life of Thiodan after fieldapplication.

Further objects and advantages of the present invention will appearherein.

In accordance with the present invention it has now been found that thedecomposition of Thiodan during storage under normal conditions as wellas under such conditions as elevated temperatures or ultravioletradiation is retarded by adding to Thiodan" relatively small amount ofcertain chemicals, thus obtaining a product of improved stability. Thechemical compounds which have now been found to act as stabilizers arecompounds containing the radical Preferably between about 0.01 andfifteen percent by weight of the chosen stabilizer of this invention isadded to the Thiodan in order to realize the most advantageous results.

The following is an illustrative list of stabilizers contemplated by thepresent invention, it being emphasized that the list is intended asmerely illustrative and not limitative.

Amides may be employed having the formula:

0 R R- N wherein each R is selected from the group consisting ofhydrogen, alkyl, cycloalkyl, aryl, alkaryl and mixtures thereof.Examples of amides include formamide, acetamide, caproamide, caprarnide,acrylamide, oleamide, cinnamide, cyclopentanecarboxamide,phenylacetamide, N- methylformamide, N-cyclohexylcaprarnide,acetanilide, stear-p-toluide, phenylacetanilide, N,N-diphenylacetamide,etc.

Ureas may be employed having the formula:

wherein each R is defined as above. Examples of ureas include urea,methylurea, sym-diallylurea, tetrabenzylurea, tetra-p-tolyurea,N,N'-di-p-tolyl-N,N-dibenzylurea, cyclohexylurea, phenylurea,n-octadecylurea, etc.

Polyamides may be employed having the formula:

\ it i N-C--(CH:)n-CN wherein each R is defined as above and n is aninteger from 0-8. Examples of polyamides include oxamide, succinamide,malonanilide, N,N'-dimethyloxamide, adipamide, malonamide,ethylmalonamide,a,u-dimethylpimelamide, decandicarboxamide, etc.

Additionally, other compounds containing the radical O i J-N may beemployed: such as imides, for example, succinimide, glutarimide,maleimide, 1,2-cyclohexanecarboximide, etc.; secondary and tertiaryamides, for example, diacetamide, triacetarnide, dipropionamide, etc.;barbituric acid and barbituric acid derivatives, for example l,3diethylbarbituric acid, 5-phenylbarbituric acid, 5,5-diethylbarbituricacid; etc.; isocyanuric acid; trimethyiisocyanuric ester; parabanicacid; hydantoin; uracil; urazole, 2,5-diketopiperazine; acetylurea;diacetylurea; etc.

The preferred stabilizing compounds of the present invention are theamides and the ureas, and, in particular urea, foramide, acrylamide andacetanilide.

In using the stabilizing compounds of the present invention it should beunderstood that they are not necessarily equivalent in their effect andcannot necessarily be used to replace one another either on a weight orchemically equivalent basis. The quantity of the stabilizing compoundused will vary with the particular stabilizer used, the method ofincorporation and the degree of stabilization desired. The degree ofstabilization desired will naturally depend upon the storage conditionssuch as time, temperature, etc. In general, however, from about 0.01 toabout fifteen percent of stabilizer by weight of Thiodan will beeffective.

The stabilizers of the present invention should preferably beincorporated with Thiodan in such a manner that the stabilizer isintimately and more or less uniformly distributed throughout the bulk ofthe Thiodan, although good stabilization is obtained when thestabilizers of the present invention contact only a small percentage ofthe exposed Thiodan area. Alternatively, the stabilizer may be added toa solution of Thiodan" and any convenient solvent, e.g., a solvent usedin the manufacturing of the Thiodan or a solvent normally used inapplying Thiodan as a pesticide, such as methylene chloride, chloroform,carbon tetrachloride, benzene, toluene, xylene, cyclohexane,cyclohexanone, etc. The solvent may or may not be subsequently removedor the Thiodan itself may be removed; that is, the solvent may beremoved by a suitable method such as by distillation, or the Thiodan"may be removed by a suitable method such as by crystallization, or theThi0dan"-stabilizer-solvent solution may be used as a pesticidalformulation as such or after the addition of emulsifiers and otherchemicals generally incorporated in pesticidal formulations. Although itis preferred that the stabilizer be added to the Thiodan in such amanner as to insure intimate distribution throughout the bulk of theThiodan, it is not intended that this invention be restricted by thispreference. For example, stabilization may be achieved by passing moltenThiodan through a column of solid particles of an appropriatestabilizing material of the present invention, e.g., urea shot. It hasalso been shown, for example, that the rate of evolution of sulfurdioxide and hydrogen chloride from Thiodan may be significantly reducedby adding the stabilizer to the top of a mass of 'Ihiodan" flakes packedin a container.

The stabilizers may be either normally liquid or normally soliddepending upon the particular stabilizer chosen. The stabilizer may beemployed in their normal form, or may be employed in the form of asolution or emulsion with water and/ or with an organic solvent ifdesired. A single stabilizer of this invention may be employed ormixtures of two or more different stabilizers may be employed.

The novel, stable compositions of the present invention may be storedwith notably less decomposition than unstabilized Thiodan. The presenceof the stabilizer has been found to exert no deleterious eliect as toherbicidal, fungicidal, insecticidal or other properties.

The data tabulated in Tables I, II and III were obtained from threeexperiments in which different samples of Thiodan were used. Each samplehad a separate history of manufacture and previous storage and it is tobe expected, therefore, that these samples will decompose at a differentrate. Each sample listed in Tables 1V and V represents different samplesof Thiodan, and again these should therefore decompose at differentrates.

It was necessary to set up accelerated Thiodan" decomposition tests inorder to demonstrate in a relatively short period of time theeft'ectiveness of the stabilizers disclosed in this invention. Thestorage of Thiodan" at a temperature greater than room temperature andthe exposure of Thiodan to ultraviolet radiation was the basis of twodecomposition tests. These conditions, especially exposure toultraviolet radiation, increase the rate of decomposition of Tniodan."After field application Thiodan becomes exposed to sunlight; hence, theultraviolet radiation test is of special significance in this regard. Amethod of treating Thiodan so that its stability under ultravioletradiation is increased is of value in prolonging pesticidally theeffective life of Thiodan" after application in the field.

Accelerated decomposition tests were conducted by storing andperiodically analyzing samples of Thiodan mixed with variousstabilizers. Various compositions were stored for varying periods oftime under continual exposure to ultraviolet light. To insure maximumexposure the Thiodan" mixtures were spread in thin iaycrs on glasssurfaces suspended between ultraviolet radiators. The Thiodan sampleswere analyzed chemically and by infrared comparison with samples ofknown purity.

TABLE I Assays of "Thiodan, Containing Varying Amounts of FormamideAfter Exposure to Ultraviolet Radiation for Varying Periods of TimePercent Vceks of ultraviolet exposure Example of formurnide 0 3 6 l3 l70 97 93 82 (it 58 l. (1 97 97 96 96 93 0. 5 97 96 G6 91 85 0.2 97 96 9187 81 TABLE II Assays of "Thiodan, Containing 0.5 Percent of VariousStabilizers, After Exposure to Ultraviolet Radiation for Varying Periodsof Time nmz'de After Storage at 70 C. for Varying Periods of T inzeWeeks of storage at 70 0. Example Stabilizer 16 none til 94 SS 17Iormamidc U4 {it til The stabilizers disclosed in this invention areeffective in reducing or eliminating the evolution of sulfur dioxide andhydrogen chloride. Data is presented in Table IV concerning the effectof formamide on hydrogen chloride and sulfur dioxide evolution fromvarious and distinct samples of Thiodan that had been stored in glassjars at room temperature. Of the two gases, only hydrogen chloride fumesin moist air. This was the basis for a qualitative test for this gasover the Thiodan" samples. Odor is a good indication of the presence ofboth sulfur dioxide and hydrogen chloride and is recorded in Table IV asheavy, moderate, slight and bland.

TABLE IV Assay, Odor, and Hydrogen Chloride Evolution After Storage ofVarious Samples of "Thiodan" Stabilized With 0.5 Percent of FormamideAfter eighteen weeks storage Original Example assay No stabilizerContained iormaniido Assay Odor H01 Assay Odor HCl 98 9? heavy..., yes9T hlanrL no.

93 S8 heavy... 91 bland. no.

91 70 slightcn 92 bland. no.

9-1 73 heavy." 91 bland. no.

95 85 heavy". yes 89 bland. no.

TABLE V Odor and Hydrogen Chloride Evolution of Various Samples ofThiodan" Stabilized by Adding 0.5 Percent of F ormamide to Solid"Thiodan Flakes and Stored Eighteen Weeks No stabilizer Containedtorniamidc Example Odor H Cl Odor H Cl moderate no.. slight. no.

moderate. no... slight no.

heavy... yes moderate. no.

. heavy..." yes... slight... no.

licavy slight no.

This invention may be embodied in other forms or carried out in otherways without departing from the spirit or essential characteristicsthereof. The present embodiment is therefore, to be considered as in allrespects illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims, and all changes which comewithin the meaning and range of equivalence of the claims are intendedto be embraced therein.

I claim:

1. A composition of matter consisting essentially of6,7,8,9,10,10-hexachlorol,5,5a,6,9,9a hexahydro 6,9-methano-2,4,3-benzodioxathiepin-3-oxide, and as a sta bilizer therefor,which retards decomposition, from about 0.01 to about 15% by weight of acompound containing the radical:

which compound is selected from the group consisting of amides havingthe formula:

wherein each R is selected from the group consisting of hydrogen, alkyl,cycloalkyl, aryl, alkaryl, and mixtures thereof, ureas having theformula:

g /N- -N R R wherein each R is selected from the group consisting ofhydrogen, alkyl, cycloalkyl, aryl, alkaryl, and mixtures thereof,polyamides having the formula:

wherein each R is selected from the group consisting of hydrogen, alkyl,cycloalkyl, aryl, alkaryl, and mixtures thereof.

3. A composition of matter according to claim 1 wherein said stabilizeris an urea having the formula:

wherein each R is selected from the group consisting of hydrogen, alkyl,eycloalkyl, aryl, alkaryl, and mixtures thereof.

5. A composition of matter according to claim 1 wherein said stabilizeran imide selected from the group consisting of succinimide, glntarimide,maleimidc, and 1,2- cyclohexanecarboximide.

6. A composition of matter according to claim 2 wherein said stabilizeris formamide.

7. A composition of matter according to claim 2 wherein said stabilizeris acrylamide.

8. A composition of matter according to claim 2 wherein said stabilizeris acetanilide.

9. A composition of matter according to claim 3 wherein said stabilizeris urea.

10. A process for stabilizing 6,7,8,9,10,l0-hexachlor0- 1,5,5a,6,9,9ahexahydro 6,9 methano-2,4,3 benzodioxathiepin-S-oxide which comprisesadding thereto as a stabilizer therefor which retards decomposition fromabout 0.01 to about fifteen percent by weight of a compound containingthe radical i JPN which compound is selected from the group consistingof amides having the formula:

wherein each R is selected from the group consisting of hydrogen, alkyl,cycloalkyl, aryl, alkaryl, and mixtures thereof, ureas having theformula:

wherein each R is selected from the group consisting of hydrogen, alkyl,cycloalkyl, aryl, alkaryl, and mixtures thereof, polyamidos having theformula:

wherein each R is selected from the group consisting oI hydrogen, alkyl,cycioaikyl, aryl, allraryl, and mixtures thereof, and n is an integerfrom O to 8, succinimide, glutarimicic, maleimide,1,Z-cyclohexanecarboximide, diacetamide, triacetamicle, dipropionamidc,1,3-diethylharbituric acid, S-phenylbarbituric acid,5,5-dielhylbarbituric acid, isocyanuric acid, trimethylisocyanuricester, parabanic acid, hydantoin, uracil. urazolc, 2,5-diketopipenazine, ncetylurea, and diacetylurea.

No references cited.

1. A COMPOSITION OF MATTER CONSISTING ESSENTIALLY OF6,7,8,9,10,10-HEXACHLORO- 1,5,5A,6,9,9A - HEXANHYDRO - 6,9METHANO-2,4,3-BENZODIOXATHIEPIN-3-OXIDE, AND AS A STABILIZER THEREFOR, WHICHRETARDS DECOMPOSITION, FROM ABOUT 0.01 TO ABOUT 15% BY WEIGHT OF ACOMPOUND CONTAINING THE RADICAL:
 10. A PROCESS FOR STABILIXING6,7,8,9,10,10-HEXACHLORO15,5A,6,9,9A, - HEXAHYDRO - 6,9 -METHANO-2,4,3, - BENZODIOXATHIEPIN-3-OXIDE WHICH COMPRISES ADDINGTHERETO AS A STABILIZER THEREFOR WHICH RETARDS DECOMPOSITION FROM ABOUT0.01 TO ABOUT FIFTEEN PERCENT BY WEIGHT OF A COMPOUND CONTAINING THERADICAL